The compound semiconductor is used in various fields such as a high-speed electronic device represented by a high frequency device and an optical device represented by a light emitting/light receiving device, and high-performance devices have been developed for practical use.
However, when a difference between the refractive index of a crystal layer forming a light extraction face and the refractive index of the air is large, it is not possible to extract light efficiently. Furthermore, even when the surface of the light extraction plane is subjected to surface roughening, poor reproducibility of the roughness causes device characteristics to be non-uniform among devices. Improvement of the light extraction efficiency is desired in the semiconductor light emitting device.